Geographic variation and temporal population differentiation of chum salmon Oncorhynchus keta from some regions of the Russian Far East

Allozyme variation of chum salmon Oncorhynchus keta was examined in the populations from nine rivers of the Russian Far East. A total of 12 loci were tested, and eight of these were shown to be polymorphic. The greatest contribution to the samples differentiation was made by the EST-D1* and sIDHP-2* loci. Most of the allele diversity was distributed among the individuals within the samples. The among-sample differences within races were statistically significant and accounted for slightly more than 7% of total variation. The differences between the races constituted 0.1% and were statistically nonsignificant. Genetic similarity of seasonal races within single locality allowed suggestion on their secondary formation after settling of founder population into a certain region.